<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Title</title>
        <script src="../js/jquery-3.4.1.min.js"> </script>
        <style>
            div{
                width:90px;
                height:40px;
                background-image:url(../images/over.png);
                float: left;
                margin-left:20px;
                text-align: center;
                line-height: 40px;
            }
        </style>
        <script>
            $(function(){
               $("div").mouseover(function(){
                   $(this).css("background-image","url(../images/out.png)");
               });
               $("div").mouseout(function(){
                   $(this).css("background-image","url(../images/over.png)");
               });
            });
        </script>

    </head>
    <body>
        <div>嘻嘻</div>
        <div>哈哈</div>
        <div>呵呵</div>
    </body>
</html>